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Do opamps have current limit, I have an OP-27 dual supply connected to 2 9V batters the battery measures 3 Amps and 16 volts is this too much current?
berkeman
Aug8-09, 10:49 PM
Do opamps have current limit, I have an OP-27 dual supply connected to 2 9V batters the battery measures 3 Amps and 16 volts is this too much current?
There is some circuit problem. The OP27 is a standard opamp, so it will not draw or drive currents much over a few 10's of milliamps.
http://www.analog.com/en/other/militaryaerospace/op27/products/product.html
Check the power connections (maybe the +/- supplie connections are reversed?). Also, be careful to take usual ESD/handling precautions, as touching a powered-up exposed circuit can cause latchup.
When you power up your circuit (assuming the 9V batteries aren't dead by now), what gets hot?
There is some circuit problem. The OP27 is a standard opamp, so it will not draw or drive currents much over a few 10's of milliamps.
http://www.analog.com/en/other/militaryaerospace/op27/products/product.html
Check the power connections (maybe the +/- supplie connections are reversed?). Also, be careful to take usual ESD/handling precautions, as touching a powered-up exposed circuit can cause latchup.
When you power up your circuit (assuming the 9V batteries aren't dead by now), what gets hot?
resistors I put on the + supply got hot anything less than 10k just burned
berkeman
Aug8-09, 10:54 PM
Can you post your schematic? Something in the middle must be hooked up wrong. If you do not load the opamp, are the currents small?
Can you post your schematic? Something in the middle must be hooked up wrong. If you do not load the opamp, are the currents small?
Its a very simple 2 opamp circuit so it must be the op amps I will replace them.
But my opamps were brand new, when I connect the batteries to the opamp circuit I connect the ground first then + then -, is this ok or is it damaging the amps?
berkeman
Aug9-09, 12:18 AM
But my opamps were brand new, when I connect the batteries to the opamp circuit I connect the ground first then + then -, is this ok or is it damaging the amps?
Not sure without a schematic. Generally you should use a DPDT switch to connect both of the rails at the same time.
Mike_In_Plano
Aug9-09, 01:38 AM
Sounds like it's mis-wired. It's easy to run high currents through the device's substrate. For example, just reversing the power supply connections will draw a huge current, while only dropping about .6-1 volt.
-Mike
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